Chimney Cowl Fitting

Chimney Cowl Fitting - How To Fit a Chimney Cowl

About Roofing’s Guide on How To Fit a Chimney Cowl

Fitting a chimney cowl can be a DIY job, providing you take care to understand what needs to be done before going ahead. If you’ve decided you could benefit from fitting a chimney cowl in your home, read on to find out how you go about installing one correctly.

Looking for a new chimney cowl? Take a look at our range of chimney cowls.

What are chimney cowls used for?

Chimney cowls are fitted over the chimney or flue and work by preventing downdraught from entering a building and encouraging updraughts to push the smoke up and out. This will help to ensure that smoke doesn’t get pushed down your chimney and into your home, which could occur on windier days. They also function as rain guards and will prevent the ingress of water as well as discouraging birds and other animals from setting up home inside your chimney.

Usually, if you light a fire, the warm air rises, propelling the smoke out of the chimney pot and into the sky. Adverse weather conditions, however, can mean that smoke is pushed downwards, which can not only cause unpleasant smells and smoke damage in your property but can also send dangerous gases into your house, which could be toxic. In worst-case scenarios, this could even cause a fire.

By installing a chimney cowl, any draughts can be stabilised and won’t be pushed down into the home. A chimney cowl also helps to increase flue draw, therefore making burning fuel last longer, so it is more economical and better for the environment too.

Fitting a Chimney Cowl

If you’ve decided that your property could benefit from a chimney cowl, you can opt to ask a tradesman to help fit the cowl, or you can choose to install it yourself. If you decide upon the latter, it’s vital to ensure you have safe access to your chimney top via the rooftop before you start work.

Make sure you have the correct sealant type if required - if it’s tile, you can use a silicone sealant to caulk the mount variant. However, a metal flue doesn’t require a sealant as when the metal heats up this could become damaged.

Chimney Cowl Fitting

Cowl fitting - what does the job involve?

Because there are many different types of chimney pots, fitting might be slightly different depending on your design, and whether you want the cowl to act solely as a downdraught suppressant or also require it to keep out nesting birds and wildlife. There are a number of different chimney cowls to choose from, so browse our range and ensure that you take a look at the specifications and features and select the one that best suits your needs.

Once you have installed a multi-fuel chimney cowl, it should last a lifetime and you can leave it in place even if you no longer use your fireplace. You can choose a cowl specific to the fuel type your fireplace requires, though a multi-fuel chimney cowl covers all your bases and means if you change the fuel type in the future, it will still work effectively.

Once you have decided on your chimney cowl, the installation job itself is relatively simple, and typically merely involves fixing the cowl by attaching an adjustable metal strap to the current chimney pot.

Firstly you need to make sure that you have identified the correct chimney pot to work on. You can do this by lighting a fire and observing which chimney the smoke comes out of to ensure you don’t accidentally fit the cowl to a neighbouring houses pot, or one that is not in use.

If you can access your chimney pot from the roof safely and easily, you can then set about fitting your chimney cowl. If your roof is pitched at a steep incline, or you don’t have the correct equipment, however, you may wish to hire a tradesperson to do the work.

First, you might need to separate the straps that need to be fixed to the cowl before installation, then add these straps to the cowl. Once you have done so, place the cowl central and flat on top of the chimney pot, before unfurling the strap and familiarising yourself with the quick adjustment hinge.

From here, you can loop the strap around the chimney, engage the clip into the start and make sure that you take up all the slack, ensuring that you don’t miss any of the fixing straps while doing so.

Next, you need to engage the hinge into its lock position and tighten the clip, making sure the strap is level and parallel.

Adjust the cowl and give it a wiggle prior to the final tightening process, to make sure it stays firmly in place. If you are going to leave a long tail on the clip make sure you are able to attach it back to the surface of the chimney pot, if you can’t do so it’s advisable to cut it off so the wind doesn’t cause it to vibrate and create noise which will reverberate down the flue. Once you have attached or cut the tail on the clip, your chimney cowl should be secure and will immediately help to prevent downdraught and protect your home from rain, snow, and nesting animals.

Got any further questions about how to install a chimney cowl, or need some advice choosing one? The team at About Roofing would be delighted to help you! Get in touch today by calling us on +44(0) 1737 763008, email us at, or using our chatbox at the bottom right of the page.